Sexual slang is a set of linguistic terms and phrases used to refer to sexual organs, processes, and activities;[1] they are generally considered colloquial rather than formal or medical, and some may be seen as impolite or improper.[2]

While popular usage is incredibly versatile in coining ever new short-lived synonyms, old terms with originally no pejorative colouring may come to be considered inappropriate over time. Thus, terms like arse/ass, cunt,cock and fuck should not be considered "slang," since they are the inherited common English terms for their referents, but they are often considered vulgarisms and are replaced by euphemisms or scientific terminology in "polite" language.

Sexual slurs are common across many cultures and historical periods. The most common slurs directed against men historically include accusations of being a passive homosexual (Aristophanes notably enjoyed using such allusions) or of being effeminate; for example, in the Hittite military oath, oath-breakers are threatened with being made into women (a promise of either actual castration, or of divine revenge on the traitors' manhood).

In the popular jargon of many cultures, the use of sexual slang is a form of humor or euphemism that often creates controversy over its public use. Sexual humor has been seen in many circles as crude and unsophisticated, as well as insulting towards the subject it describes. Sexual slang has a long history in literature and comedy: examples from Shakespeare are well-known. The popularity of contemporary comedians who indulge in sexual humor, from George Carlin to Andrew Dice Clay, reflects the appeal of this form of speech. It is often seen as a form of taboo, in which much of the appeal lies in the shock value of daring to speak "forbidden" words in public.